Note: Descriptions are shown in the official language in which they were submitted.
93
The invention relates to an overhead cable trans-
port installation, in particular a gondola lift, comprising
at least a carriage with detachable grip for coupling a
qondola on to the cable, a device for accelerating and synchro-
nizing the said carriage before its coupling on the cable,
with at least one synchronizing wheel engaging the said
carriage by frict:ion in the area above the coupling point,
in relation to the direction of travel of the cable and
- driven by rotation at a tangential speed synchronous to the
cable, and a device for testing the clamping of the said
grip in the area below the said coupling point capable of
exerting on the carriage coupled on the cable a braking or
accelerating force.
One known installation of the type mentioned has
a thrust system fitted in the trajectory over which moves
the carriage with grip and which is capable of exerting on
the latter an opposing braking or accelerating force.
When the grip is correctly clamped on the cable,
the carriage overcomes this opposing force and continues
its travel without slipping on the cable. If on the contrary,
the clamping is insufficient, the opposing force makes the
grip slip on the cable and this slipping is detected by any
appropriate means. The opposing force applied to the car-
riage is fixed by regulations according to the characteristics
of the installation, for example by the formula 1,5 x p sin ~ ,
p being the total weight of the gondola and the load
transported, and ~the maximum angle of inclination of the
; cable along the line.
The thrust system causes shocks and oscillating
; 30 movements of the cable and the gondola which are particular-
ly troublesome. The detection device is complicated and is
incapable of taking into account variations in the speed of
,
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the haulage cable.
Another known installation has a carriage thrusting
or braking chain capable of exerting an opposing testing
force. The dynamic force necessary for driving this chain
causes vibration and oscillation incompatible with the cor-
rect operation of the measuring device.
The object of the present invention is to remedy
these disadvantages and to permit the execution of a parti-
cularly simple and reliable installation.
The installation according to the present invention
is distinguished by the fact that the said device for testing
the clamping has at least one test wheel capable of engaging
the said carriage by friction, a means of rotating the said
test wheel to bring this to a speed synchronous with that
of the cable before the carriage is engaged on the said test
wheel and to exert on the said test wheel an opposing force
tending to impose on the test wheel a speed different from
that of the cable during the said engagement and a detector
of a differential speed between the said test wheel and the
said cable.
The device for testing the clamping of the grips
can be added to a standard installation without any modifi-
catlon o~ this, and can be installed on an existing gondola
lift. The test wheels, advantageously equipped with
pneumatic tyre, are arranged so as to follow the usual
synchronizing wheels, and in accordance with a development
of the invention, the slipping of the grip on the cable
is signaled by the detection of a diffcrence in speed
between the synchronizing wheels and the test wheels. In
standard install~tions, the synchronizing wheels are
driven at a speed synchronous with that of the cable, in parti-
cular by a direct take-off movement from the cable.
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3~!~3
The test wheels are driven by a motor at a speed
synchronous with that o~ the cable, and during the slip
detection phase, the motor is transformed into a generator
exerting the opposing force on the carriage. The motor
may be electric, mechanical or pneumatic, the electric motor
being easily synchronized with the running speed oE the
cable.
According to a development of the invention the
opposing forces exerted on the carriage is a holding-back
force easily obtained in the case of an electrical drive
by the simple interruption of the power supply to the motor.
The holding-back force is applied gradually, and avoids any
violent shock that could involve jerks or oscillating of the
cable of the gondolas.
The need to take consideration variations in the
speed of the cable, due in particular to variations in the
load, is avoided, by detecting a difference in speed between
the synchronizing wheel and the test wheel. This difference
may be observed by coupling a tachometric generator with
the synchronizing wheel and to the test wheel a second
tachometric generator the signals from which are transmitted
to a unit detecting the difference. This particularly
simple test system makes it possible to verify the correct
operation of the drive or testing device during the phase
preceding the testing of ~he clamping and to indicate any
slipping of the grip during the test phase.
The installation advantageously includes a means -
for testing the correct positioning of the grips clamped on
the cable. This test is carried out by means of geometrical
gauges installed in the trajectory followed by the moving
grips and indicating any incorrect positioning.
Other advantages and features will emerge more
335~3
clearly from the followin~ account of a mode of application
given as a non-restrictive example, and shown in the attached
drawing, in which the single figure shows s~hematically a device
for testing the clamping of a grip in accordance with the
invention.
In the figure, a carriage 10 runs on wheels 12 on
a rail 14 of a terminal station of an overhead cable trans-
port installation, in particular of a ~ondola lift. Carriage
10 is equipped with grips 16 for coupling on to a haulage-
track cable 18 extended between the two terminals. A gondola
(not shown) is carried by a suspension 20 hinged on the grip
carriage 10. The grips 16 are of the detachable type permit-
ting the uncoupling of the carriage 10 from the cable 18 in
the terminals and the running at a slow speed or the stopp-
ing of the gondola at the loading or unloading platforms. At
the exit from the station, the carriage 10 is accelerated,
by gravity for instance, by running on an inclined section of
rail, and its speed is synchronized with that of the cable
18 by means of three synchronizing wheels 22, 24! 26 engaging
a running surface 28 provided on the upperside of the carriage
10. The synchronizing wheels 22, 24, 26 equipped with pneumatic
tyres, are staggered in the direction of travel of the
carriage 10, indicated by an arrow in the figure, and are
rotated at a linear speed equal to that of the cable 18 by
a movement take-off (not shown) on cable 18 of a type well
known to experts. A control device (not shown) situated at
the level of the synchroni2ing wheel 24, brings about the
closing of the grips 16 and the coupling of carriage 10 on
to the cable 18, which then hauls the carriage 10. In the
position of carriage 1~ shown in the figure, the grips 16
have just been closed on the cable 18 and the carriage 10
enters the section for the testing of the clamping of grips 16.
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Four wheels 30, 32, 34, 36, identical with synchroni-
zing wheels 22, 24, 26, are staggered along tlle test section,
and each of these is equipped with a pneumatic tyre which
engages running surface 28. The test wheels 30 to 36 are
interconnected by means of universal joint transmissions
38, and also connected with a motor 40. The latter can be
an hydraulic motor or advantageously a direct current elec-
tric motor. The transmissions 38 ensure a perfect synchroni-
zation of the rotation speeds of test wheels 30 to 36, and
the assembly of synchronizing wheels 22 to 26 and test wheels
30 to 36 is mounted on a frame (not shown), adjustable in
height in relation to rail 14 in order to ensure paralle-
lism and an equality of the pressures transmitted to the
carriage 10 by the various wheels.
The synchronizing wheel 26 drives a tachometric
generator 42, the signal from which is transmitted to a unit
44 supplying power to and monitoring motor 40. The test wheel
30 drives a tachometric generator 46, identical with genera-
tor 42, and the signals emitted by the generators 42, 46 are
applied to a detectlon unit 48, signalling any difference in
speeds between the generators 42, 46. The power supply and
monitoring unit 44 receives a signal on the entering of the
test section by carriage 10, emitted by a switch 50, action-
ed by a thrust 52 acting in conjunction with the running sur-
face 28 of the carriage 10.
The generator 42 controls the power supply and
monitoring unit 44, in such manner as to impose a speed of
rotation of test wheels 30 to 36 by the motor 40 perfectly
synchronous with the running speed of the cable 18. At the
entrance to the test section, are fitted geometrical gauges,
of a known type, which verify the correct position of the
clamping jaws of the grips 16 in the closed position, clamp-
.
ed on the cable 18.
The testing device operates in the following man-
ner :
The synchronizing wheels 22, 24, 26, dri~en directly
by the cable 18, rotate constantly at a speed synchronous
with that of the cable 18. This speed is measured by the
generator 42 and the monitoring and power supply unit 44
controls -the motor 40 so as to drive the test wheels 30 to
36 at the same speed during the periods of absence of a
carriage 10 from the test section, these periods being
signalled by the closing of the switch 50. A carriage 10
that has to be coupled on to the cable 18, and accelerated
by gravity, is engaged under the synchronizing wheels 22,
24, 26, so as to move at the same speed as the cable 18 when
the grips 16 are closed, which takes place at the wheel 24.
The correct closing of the grip jaws is checked by the geomet-
rical gauges (not shown) which bring about the stopping of
the installation in the.case of an incorrect positioning.
In the case of correct positioning, the carriage 10 continues
its travel, and is engaged under test wheels 30 to 36, which
rotate at the same speed, this engagement being signalled
; by the switch 50 which opens and cuts the power supply to
the motor 40. The engaging takes place withou-t any shock
and on the opening of the switch S0 the motor acts as a
brake driven by the wheels 30 to 36. The braking effort
is gradual and be accentuated or regulated by the insertion
of an electrical resistance lnot shown). The cable 18 hauls
tllc c~rriac3c alonc~ ~hc tcs~ sect;Loll agaill~t ~hc opposing forcc
exerted by the wheels 30 to 36, the motor 40 operating as a
braking generator. IE the grips 16 are correctly clamped,
the carriage 10 pursues its travel at the same speed as the
cable 18 without any slipping of the grips. When there is
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incorrect clampin~, the bLaking foLce exerted by the test
wheels 30 to 36 on the carriage 10 causes the slipping of
t:he grips 16 on the cable 18, and the speed of movement of
t:he carriage 10 becomes lower than that of the cable 18. The
cletector 48 signals any difference in speed between the syn-
chronizing wheels 22, 24, 26and the test wheels 30 to 36.
During the test phase the speed of the test wheels corresponds
with that of the carriage 10, and in the case of the slipping
of the grips 16 this speed is different from that of the
cable 18, corresponding with that of the synchronizing wheels
22 to 26. This difference in speed due to a slipping of the
grips 16, is signalled by the detector 48, which advantageously
causes the stopping of the installation. The switch 50 may
be of the delayed-action type, closing after the carriage
10 has passed on to the test section. On the closing of the
switch 50 the motor 40 supplied with normal power imposes
on the test wheels 30 to 36 a speed synchronous with that
of the synchronizing wheels 22 to 26~ The detector 48 also
signals any synchronization defect, that is any malfunctioning
of the motox 40 regulating device.
It is easily seen that the test device functions
independently of the running speed of the cable, any variation
in speed being automatically repercuted on the speed of the
synchronizing wheels 22 to 26 and the test wheels 30 -to 36,
without actioning of the detector 48. The difference in
speed between the wheels 26, 30 can obviously be detected in a
different manner, in particular by a mechanical, phonic or
optical sensor, and the scope of the invention will not be
exceeded by modifying the number of synchronizing or test
wheels and in using a different means of driving and/or
braking the test wheels 30 to 36. The test device according
of the invention is advantageously installed at the exit of
.
each terminal, and if necessary of intermediate stations of
the installation, the test being carried out on all the
gondolas, whether loaded or empty. The test device has been
described in its preferred mode of application, ln conjunction
with the device for synchronization and coupling of the
carriage on the cable, but it is clear that the test may be
effected at a different position, the synchronizing wheel
then serving only as a wheel to measure the running speed of
the cable 18. The test may be effected by an oversupply to
the motor 40 tending to accelerate the gondolas lO, the
testing force being applied in both cases gradually, and in
a perfectly controlable manner, to avoid any shock or oscil-
lation. The test device makes use of standard components and
can be easily mounted on an existing installation or supplied
at the customer's request without any great modification of
the standard installation.
...
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